Of all the strange spiky
botanical forms thriving in the Sonoran desert, some of the most spectacular
and extravagant are the agaves. Flowering stalks of agaves begin to emerge as
the weather warms in spring, and depending on the species, may grow to over
twenty feet tall! Their
reproductive strategy is known colloquially as "boom and bust"
reproduction, because the plant will live for many years as a leafy rosette,
and then shoot up a stalk bearing hundreds or thousands of flowers in one
season. The plant uses so much energy in the process that it dies after the
seeds have ripened. The academic term for this is "monocarpic
perennial," which translates to "a plant that lives for many years
but only produces seeds once." Although agaves are sometimes called “century
plants,” most species only live between 20-30 years.
Several years ago, I measured the daily growth of
a few specimens in our neighborhood. My records show that agave flowering
stalks will grow anywhere between 3 and 9 inches per day for one species I was
tracking, Murphey’s Agave. Murphey’s is one of several dozen types of agave found
growing in the Phoenix area, thanks to a bustling import and cultivation business
for use in ornamental landscaping. There are actually no wild agave populations
within the metropolitan region, although several species grow naturally at higher
elevations in surrounding mountains. However, there are a few small populations
of Murphey’s, also known as Hohokam Agave, that appear to be remnants of pre-Columbian
agricultural settlements. Agave has been, and continues to be, one of the most
important utilitarian and food plants for indigenous cultures throughout the
Trade between ancient cultures played a large
role in distributing agave to new areas far beyond their natural range. Many populations
now known between central Arizona and Grand Canyon appear to be what is left of
small plantations that were created to harvest for food, medicine and fiber. Both
the piña and stalk of some species
were roasted and eaten; the large stone-lined roasting pits remain as some of
the most visible archaeological features of some pre-historic settlements. The pulp and juice were also considered
to be excellent tonics and healing medicine. Stalks were used as tools, building
material and musical instruments. Fiber from the leaves was used to make
sandals, fabric and nets. Be forewarned: the sap of some species is so toxic
that it could be used as fish poison or arrow poison for hunting. As noted by historian William H.
Prescott in 1843: “The agave,
in short, was meat, drink, clothing, and writing materials for the Aztec.
Surely, never did Nature enclose in so compact a form so many of the elements
of human comfort and civilization!”
Today, huge agave plantations are an important
part of the North American economy. Tequila, mescal, agave syrup, and sisal are
some of the major products exported from Mexico all around the world.
Harvesting agaves is highly regarded as a technical skill, requiring strength
and knowledge to recognize and properly cut the mature plants. Harvesters, called jimadores, use specially designed cutting tools, called coas, to expertly remove the
spine-tipped leaves and extract the piña,
or core of the plant. Certain species are raised specifically for the fiber in
leaves, which is used to produce everything from rope to place mats. Other
species are best for the sweet sap that can either be pressed out and fermented
to brew tequila, or reduced to make honey-like syrup. Industrial researchers
are currently investigating the use of agave to produce bio-fuels.
Despite the stunning effort put into seed
production, very few of the tens of thousands of seeds made by a single agave
actually germinate and grow into mature plants. For many species, most
reproduction is from plantlets that emerge either on the stalk, called bulbils,
or from the roots of the parent plant, called “pups” or hijos (Spanish for “sons”).
These smaller plants are the form that has been most easily traded for
thousands of years, and allows us to now enjoy so many kinds of agaves in the
suburbs of Phoenix. Part of the
job of an jimadore on an agave
plantation is to extract the parent plant without destroying the hijos. Likewise, if you have the
privilege of witnessing the flowering and passing of an agave in your home
landscape, be sure to collect the hijos
and find a good home for them to carry on their line of noble plants.
Since May 2005, I have written a natural history column for a neighborhood newsletter published by Jennifer Moore called "Our Big Backyard: Natural History of the Deem Hills," and since 2010, "A Suburban Naturalist."All of these columns are reproduced here. Deem Hills is a City of Phoenix Desert Preserve located just north of Happy Valley Road in north central Phoenix, and just west of I-17. The Preserve and adjacent hills comprise over 900 acres of open space with several miles of hiking trails. For more perspectives from the Deem Hills and suburban Phoenix, also check out my companion blog, Kat Tracks.
As a naturalist with a special interest in botany and plant ecology, some of my greatest passions are to explore, photograph and write about native plants. If I can spark an awareness or interest in natural history in others along the way, that is my greatest reward.